In sports shoes, sneakers, overshoes, boots, saddle shoes and the like, an upper portion made of cloth or synthetic resin and a shoe sole made of synthetic resin, rubber or leather are completely integrated with each other by sewing or gluing. In particular, it has been considered that the sewing or gluing technique is important in order to enhance strength, durability and the like of the shoes.
In shoes hitherto, an upper portion and a shoe sole have been integrated with each other; therefore, they could not be separated from each other. As a consequence, if either one of the upper portion and the shoe sole has been broken, the shoes as a whole is to be disposed or left in a shop or the like for repair, so that the shoes could not be used. Furthermore, in the case where shoes are limited to use at only indoors or outdoors, a user must prepare a pair of substituted shoes and change the shoes when he or she moves from that location. Moreover, various designed shoes full of variety have been commercially available in recent years, and it is general for the user to select ones of his or her shoes and change them in accordance with circumstances. Accordingly, if only the upper portion could be separated from the shoe sole and exchanged with another upper portion, storage spaces of the shoes can be saved since that the number of bulky shoe soles (which is solid and cannot be folded) can be reduced more than that of the upper portions, and that the shoes as a whole are not bulky; thereby providing convenience. However, such shoes as described above have not been found. Thus, the inventor of the present invention has studied the footwear in which both of an upper portion and a shoe sole are exchangeably used.